1. Field of the Invention
The present invention relates generally to a manway cover, and more specifically to a manway cover with an integrated cleaning system for cleaning a tank or other enclosed structure.
2. Background
Enclosed storage structures such a tanks are well known in the art. These storage enclosures are used to store a wide variety of liquids and solids, depending on the industry in which the storage enclosure is being used. In the oil and gas industry, for example, holding tanks and shipping tanks are used in oil field production. Further, storage tanks are used to hold fluids used in hydraulic fracturing (“fracking”). Some of these fracking tanks are enclosed structures, where human access to the interior of the tank is limited to a manway. These fracking fluids, which may contain relatively high levels of solids such as sand, are stored until their use at the job site. The interior of the tanks described above, as well as a variety of other enclosed tanks, must be cleaned regularly to ensure proper fluid flow and a “clean” course of fluids for downstream use. Cleaning the interior of enclosed tanks and other structures presents a variety of challenges.
Access to the interior of steel tanks such as those described above is generally via a manway that is closed and sealed with a manway cover. This limited access makes it difficult for an individual to position himself to properly clean the interior of the tank using a hose or other mechanism for introducing water or cleaning fluid into the tank. Further, cleaning methods that require an individual to enter the tank in order to properly clean the interior expose the individual to the substances that were stored within the tank, some of which may be hazardous or otherwise undesirable.
Tanks may be designed to make cleaning easier, however a large number of existing tanks are used across various industries, and the tanks have a relatively long lifespan. The cost of the tanks coupled with the remaining long life of existing tanks provides a disincentive to replace existing tanks for a newer model that may be easier to clean. What is needed is an effective cleaning system for use with steel tanks and other storage enclosures accessed via manways, the system being capable of easy retrofit to a wide variety of existing tanks.